This invention relates to an indicator.
Quick couplers for mounting an attachment, e.g. a bucket, to an earth working machine, such as an excavator, are known. A potential danger with a quick coupler is that the coupler can fail to hold the attachment at one or both of the mounting points with the result that the attachment can either fall off the coupler or swing down from the coupler.
The failure to correctly hold the attachment in place can be due to a variety of reasons. If the quick coupler is hydraulically operated an hydraulic failure can result in the quick coupler failing to retain the attachment in a working position. Another reason can be failure to correctly locate a pin of the attachment in the coupler. For example, when the pin is retained by a sliding wedge component, failure to fully locate the pin in the recess in the coupler can result in the wedge sliding over rather than under the pin. Consequently the pin will not be locked in the recess.
The consequences of such failures can be injury to, or death of, someone in the vicinity of the attachment.
When the coupler is mounted to the earth working machine such as an excavator, one end (usually referred to as the front end because it is closest to the operator) is readily visible to the operator. Thus it is usually the case that the correct location of the pin in the front recess of the coupler and subsequent locking of the pin in the recess is visually apparent to the operator.
However, the location and locking of the rear pin of the attachment in the rear recess of the coupler is not visible to the operator. Therefore there is a need for some form of indicator whereby an operator has a visual indication that the rear pin is engaged and locked prior to operating the machine to lift the attachment.